Windows 8 - Slow Shared Folders in Office

I have Windows 8 running in Parallels 8.0.18101. I have had continuous problems with slow access to shared folders from the Mac side since I upgraded to Windows 8. I followed advice I saw earlier in the forums with uninstalling the parallels tools (which was not easy because it hung on removal at first), restarting the guest, then reinstalling parallels tools. This improved the slowness but has not fixed it.

Specifically, here are the symptoms:

1. When I open a shared folder to browse, it's works fine
2. When I open a text document, it opens immediately
3. When I open any office document, it hangs with "Contacting Y:\XX.xls" (or .doc or whatever), sometimes up to 10-15 seconds.

Any ideas?